(a) In addition to any other fines and penalties, any local public agency which owns or operates vehicles used for the collection of garbage, refuse, or rubbish and which has, within any 90-day period, been convicted an excessive number of times for operating those vehicles in violation of any of the weight limitations set forth in Chapter 5 (commencing with Section 35550) of Division 15, taking into consideration the total number of trip routes for those vehicles which are normally scheduled in the same 90-day period, may be assessed a civil penalty not to exceed two thousand five hundred dollars ($2,500) for each violation. Nothing in this section affects the legal standards, proof requirements, or penalty provisions of any other provision of the law.